Accumulators of the type having a fluid on each side of a movable member, such as a diaphragm or a piston, wherein depletion of the fluid on one side of the member causes movement of the member and energizes a signal is already known in the art. U.S. Pat. Nos. 2,484,177 and 3,008,548 and 3,224,816 and 3,363,074 are related to safety signals for vehicle brake systems. The prior art is therefore aware of the utilization of accumulators for signaling the loss of fluid pressure in a system, such as a vehicle brake system.
However, the present invention is an improvement upon the prior art in that it provides an accumulator which is utilized for a vehicle brake system and which has hydraulic oil on one side of a movable member and which has a gas on the other side of the movable member, and the present invention provides a means for detecting the depletion of the gas and the consequent loss of its pressure and consequently there is a safety warning system. Still further, the present invention provides means for accomplishing the aforementioned by utilizing either a sliding piston or a flexible diaphragm, both of which are disposed within a fluid-tight container and which move in a direction to complete an electric circuit for purposes of creating an electric signal in the warning system.
Still further, the present invention provides an accumulator warning system of a multiple stage type and wherein it can be utilized for detecting the depletion of a gas pressure in a vehicle brake system, for instance, and the first stage of warning may be a preliminary warning with the activation of a preliminary warning signal, and the subsequent stage or stages can then provide additional or final warning as to a more serious or complete depletion of a fluid pressure in the accumulator. Still further, the present invention provides an accumulator warning system wherein the apparatus is reliable and sturdy and can be readily and easily provided and is capable of continuous and repeated operations, and the system is basically arranged so that it will not be self-damaging but will actually provide for extended movement of the movable parts without interfering with the warning operation and without damaging itself.
Accordingly, the present invention provides an accumulator warning system which is useful in vehicle steering systems, brake systems, and in other installations where pressurized fluids are employed, and the system provides an early and a final warning for depletion and leakage of the fluid employed in the system and, as such, the system is in the nature of a safety device and assures that the operator will be informed as to the condition of the system, according to the energizing of a signal, either visible or audible.
Other objects and advantages will become apparent upon reading the following description in light of the accompanying drawings.